[Mercifull]

Updated 9/9/24:


Items needed:

• Narda 8616 electromagnetic radiation monitor (of course)
• 15mm copper pipe
• 22mm plastic water pipe
• 3d printed probe head - https://www.tinkercad.com/things/k0Ms4o ... 7jA6gg2XCE
• 3d printed probe handle connectors/end cap to join the two pipe sizes together - https://www.tinkercad.com/things/5e2DwT ... QzYdPQ25mY
• 3d printed Narda screw connector. its not a great model but screws on ok, just don't repeatedly take it off/on again - https://www.tinkercad.com/things/4Q1QhO ... QS5REUq1C4
• 3-core domestic electric cable
• 2 x pg7 strain relief connectors, you screw/glue it right in theres not enough space for the connecting nut
• 3d printed probe holder - https://www.tinkercad.com/things/2nPDQB ... nslOtLpTls
• M4 bolt and locknut. You'll need to drill into the side of the Narda chassis. Use sticky pads behind the holder to prevent spinning as well
• 6.35mm panel mount audio jack, you'll need to drill into the back of the chassis to install
• Red and yellow electrical tape, aluminium/silver tape
• Labels

Original post:

I recently picked up a Narda 8616 electromagnetic radiation monitor. Unfortunately it had a broken screen and shrouding.


So I designed and 3d printed a little piece that could go over where the broken bits had come off with an allowance for some Perspex to go in between.



I then dirtied it up a bit to match the rest of the unit which is clearly well worn. But I didn’t have a probe…

This led me to use some images I found online to model my representation of a Narda 8721 probe which I think is the closest match to the one in Frozen Empire. I didn’t want to 3d print the entire thing though because I thought it would be fairly weak and prone to cracking along the print lines. So u used some off the shelf parts for the handle like copper and plastic plumbing pipes.


After a few iterations of the design particularly with the head of the probe and the connector I was fairly happy with the scaling and I painted it white and designed some stickers, again roughly based on low resolution images online.

It’s not 100% accurate but I am pretty pleased by it. It’s very heavy though so I might strip out the innards and add some basic sound effects or something in the future.

[alphabeta001]

That's awesome

[Mercifull]

That's awesome

Thanks. I still need to work a bit more on the probe holder. I used an existing nut/bolt to hold it on so it's only held in place by one bolt and then tape. I need to drill another hole into the side of the meter and then I'll reverse the direction so that it doesn't poke out so much.

I'm contemplating using another Arduino to animate the needle and add sound functionality etc but might hold off for a little bit just incase I can get a real probe for a sensible price because it would be quite cool to have it genuinely working rather than just pretend.

I also acquired some vintage Sony DR-5A Stereo Over Ear Headphones. Not quite the DR-4As used in Frozen Empire but still from the same era and visually fairly similar. Interestingly it comes with a chunky 6.35mm jack and not a 3.5mm one which is the port on the meter so either the production team changed the jack type, used an adapter, or added a new port somewhere else on the meter. It's hard to tell from watching on screen and there's no decent photos of it on the Ghostbusters Reference Library.

[prodestrian]

I'm contemplating using another Arduino to animate the needle and add sound functionality etc but might hold off for a little bit just incase I can get a real probe for a sensible price because it would be quite cool to have it genuinely working rather than just pretend.

It's worth having a look at the back of the gauge to see how it's wired up, many of the ones I've modified have had an external resistor which can be easily bypassed so you can control it from an Arduino (swap it for the correct value, see my example post here). It might be a reversible change, if you decide to go down the Arduino path until you find the genuine probe.
(Only if you feel comfortable opening the device up, obviously)

either the production team changed the jack type, used an adapter, or added a new port somewhere else on the meter. It's hard to tell from watching on screen and there's no decent photos of it on the Ghostbusters Reference Library.

Looks like the headphone jack on the front isn't connected to anything in the film:


The headphones seem to be plugged into the back:


So I think you're correct, they probably added a new port on the back (as far as I can tell there's nothing in that location on an unmodified Narda, based on the eBay listings I've been scrolling through).

[Mercifull]

So I think you're correct, they probably added a new port on the back (as far as I can tell there's nothing in that location on an unmodified Narda, based on the eBay listings I've been scrolling through).

Good spot. At the moment I've been using an L shaped 6.35-3.5mm adapter (otherwise its too tall to fit there anyway because of the handle in the way) but I think I might install a surface-mounted jack port to the back now.

[prodestrian]

Forgot that we also see the prop in the scene at 1:10:40, get a slightly better look at the back of it:

[Mercifull]

Do you know if we ever see the probe attached to the mount on the side? I am in the process of designing a 3d printable part for this as I am currently just using a metal garage hook bent slightly out of normal shape. The indents/cutouts are odd though showing it thin towards the back and thick at the front. In contrast, the probe is thick at the back and thin at the front. Is it held on backwards? Or is the thin bit for the cable and thick bit for the handle?

[Mercifull]

Knocked something up quickly in tinkercad. Not accurate to screen because my probe is different. Should be roughly close enough looking to suffice though. It’s printing now will check it back in an hour.

[Mercifull]

Fresh off the printer.



Design looks fairly close to the screen one and the probe fits nicely.



But I think my scaling is off. I think the whole thing needs making bigger, wider and longer. Too late to make changes now so will revisit tomorrow evening instead.

[Mercifull]

I made it bigger... but when I printed it then it looked too big. So I took it down another half cm or something and I'm more happy with it now. It's not the same as the one in the movie but it’s a good enough facsimile to fit my own custom probe nicely.

It's attached with a M4 bolt and a locknut on the inside to try to stop it twisting too much. To prevent spinning (without needed to drill additional holes and ruining the look) I added some double sided adhesive tape underneath.

I've also installed a 6.35mm audio jack into the back. I didn't know exactly where to put it but given the fact that mine has already been modded with a kettle cable for charging instead of the standard A/C port on the top I figured I'd just bolt it roughly in-line with that for some sort of visual symmetry.

A touch of red electrical tape to both the probe & audio cable and some yellow on the handle and done... for now at least. Maybe I'll add some sort of animation/audio to it in the future but I need to move on to other projects.